Copyright holders seek to identify copyright violations which occur when copyrighted content, such as a copyrighted video, is pirated. Such content, to which access has been made available in violation of copyright, may be referred to as hacked video, hacked content, rogue content, pirated content, or other similar terms.
It is often the case that pirated content will be manipulated by pirates in an attempt to frustrate automatic detection systems, so that automatic detection via simple comparison becomes difficult. Such manipulations may include, for example, but not be limited to: change of color, cropping, rotation/translation, audio mute/swap, video format transcoding, etc.